Osteoarthritis affects up to 80 percent of people over 50. Severe osteoarthritis affects three times as many women as men. Symptoms range from mild pain, stiffness of one or more joints, and swelling and creaking to total loss of joint function, disrupting walking, dressing, and even sleep. Muscles may waste away around an arthritic joint, and the bones can change shape. Osteoarthritis tends to affect large weight-bearing joints, such as hips and knees, as well as small joints in the feet, hands, fingers, neck, and lower back. Symptoms may be more severe than actual physical damage.

Rheumatoid arthritis is an autoimmune disease which causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Because it can affect multiple other organs of the body, rheumatoid arthritis is a systemic illness and is sometimes called rheumatoid disease.